|#|Name (Birth–Death)|Took office|Left office|Monarch|Prime Minister|
|---|---|---|---|---|---|
|1|The Viscount Gladstone (1854–1930)|31 May 1910|8 September 1914|George V|Botha|
|2|The Viscount Buxton (1853–1934)|8 September 1914|17 November 1920|George V|Botha|
|3|HRH Prince Arthur of Connaught (1883–1938)|17 November 1920|21 January 1924|George V|Smuts|
|4|The Earl of Athlone (1874–1957)|21 January 1924|26 January 1931|George V|Smuts|
|5|The Earl of Clarendon (1877–1955)|26 January 1931|5 April 1937|George V|Hertzog|
|6|Sir Patrick Duncan (1870–1943)|5 April 1937|17 July 1943|George VI|Hertzog|
|—|Nicolaas Jacobus de Wet (1873–1960) (Officer Administering the Government)|17 July 1943|1 January 1946|George VI|Smuts|
|7|Gideon Brand van Zyl (1873–1956)|1 January 1946|1 January 1951|George VI|Smuts|
|8|Ernest George Jansen (1881–1959)|1 January 1951|25 November 1959|George VI|Malan|
|—|Lucas Cornelius Steyn (1903–1976) (Officer Administering the Government)|26 November 1959|11 December 1959|Elizabeth II|Verwoerd|
|9|Charles Robberts Swart (1894–1982)|11 December 1959|30 April 1961|Elizabeth II|Verwoerd|
|—|Lucas Cornelius Steyn (1903–1976) (Officer Administering the Government)|30 April 1961|31 May 1961|Elizabeth II|Verwoerd|

Question: how many total years did sir patrick duncan serve in office?
Answer: 6